[Bug] [Regression] Background commands don't notify Claude Code on completion

Bug Description
Background commands do not notify Claude Code on completion anymore, despite Claude thinking it would, and it being the ideal behavior.

Environment Info

• Platform: linux
• Terminal: ghostty
• Version: 2.1.19
• Feedback ID: 24834975-efb5-4d15-9715-6ddc42326d10

FYI: Tested on Mac as well - same issue, began in 2.1.19 (I believe).

Errors

[{"error":"Error: ENOENT: no such file or directory, scandir '/etc/claude-code/.claude/skills'\n    at readdirSync (unknown)\n    at <anonymous> (/$bunfs/root/claude:12:1903)\n    at cO (/$bunfs/root/claude:11:35427)\n    at readdirSync (/$bunfs/root/claude:12:1864)\n    at QFR (/$bunfs/root/claude:2213:380)\n    at QFR (/$bunfs/root/claude:2213:1350)\n    at <anonymous> (/$bunfs/root/claude:2213:4440)\n    at <anonymous> (/$bunfs/root/claude:2213:5171)\n    at A (/$bunfs/root/claude:11:7251)\n    at FK8 (/$bunfs/root/claude:4860:4342)","timestamp":"2026-01-25T00:05:06.449Z"}]

Why I need this
I'm building https://github.com/zippoxer/subtask which relied on these notifications to present subagent replies to Claude as soon as they're done, so Claude could react to them without user involvement.